Strip stock, such as thin metal strip less than about 0.010 inches thick, that has little resistance to buckling when being intermittently advanced into the work station of a punch press or the like will be most apt to buckle if the incremental feed stroke length is relatively long, e.g. 2 inches, and the cyclic rate of feed is at the same time relatively high, e.g. 300 feed strokes per minute or higher. In a high speed dual slide feeder of the type illustrated in my copending application Ser. No. 06/116,548 filed Jan. 29, 1980 and entitled Control Arrangement for Dual Slide Pneumatic Feeders, now U.S. Pat. No. 4,310,114, the stock feed acceleration forces produced by each feed slide at the beginning of each feed stroke may produce a slight buckling of that portion of the stock just in front of the feed slide that is commencing the feed stroke. Even a slight buckling of this portion of the thin stock however may interfer with the simultaneous return movement of the other feed slide that is then just beginning its index or non-feed stroke; said other feed slide here attempting during its non-feed stroke to move past said buckling portion of the thin stock. When such buckling and interference occur both of said feed slides will become stalled in the course of their respective strokes and this is particularly undesirable during high speed operations not only because of the time and material waste involved but also because of the risk of damage to the feeder, to the more expensive tooling in the punch press with which the feeder is being used, and/or to the press itself.